There are more than 5,000 US troops in Iraq, officially in the “advise and assist” capacity, training the Iraqi army and militias for their ongoing war against the so-called Islamic State (IS, formerly ISIS/ISIL).

Earlier this week, Iraqi forces began advancing on the IS stronghold of Mosul, a major city in northern Iraq with over a million inhabitants.

“There are Americans in harm’s way as part of this fight,” Pentagon spokesman Peter Cook said on Monday, though he insisted they were still only in a supporting role. OIR commanders have said that US troops would serve as forward air controllers and artillery spotters, coordinating the coalition support for Iraqi ground troops advancing on Mosul.